This application requests partial funding for the Fourth Biennial Arthritis Research Conference to be held under the joint sponsorship of the Arthritis Foundation, the American College of Rheumatology, American Academy of Orthopaedic Surgeons, the National Institute of Arthritis, and Musculoskeletal and Skin Diseases. The meeting will be held from June 27-29, 2003, at Keystone Conference Center, Keystone, Colorado. Participation will be limited to 400 attendees. All known arthritis research trainees in North America are invited to attend. Selected senior researchers are invited, based on expertise and interests that would most likely benefit from, and contribute to, the stimulating and productive environment of the Conference. Invited speakers are distinguished investigators who will present plenary lectures, chair sessions and workshops, and interact with trainees during the Conference. The plenary session is devoted to a topic of general interest to all participants, focusing on Recent Progress in Fundamental Immunology: From Innate to Adaptive Immune Responses and concurrent Basic and Clinical Science Symposiums. The Basic Science Symposium will be devoted to Basic Mechanisms of Tissue Injury. Topics include Lymphoid neogenes, Complement activation in tissue damage, Estrogen receptors in cartilage and RAGE and amplificaton of proinflammatory pathways. The Clinical Sciences Symposium will focus on Pain and Inflammation. Topics include Mapping gene loci that determine pain sensitivity; Sex differences in pain sensitivity, Key determinants of immune and inflammatory infiltrates in RA synovitis, Targeting B cells with anit-CD20 antibodies as a therapeutic approach. Twelve workshops will allow selected trainees to present their research. In addition, there will be two poster sessions, at which all remaining trainees will have an opportunity to present their work. The overall goal is to provide an interactive meeting in an informal atmosphere that facilitates comprehensive discussion of many aspects of the scientific basis of arthritis pathogenesis and related musculoskeletal diseases. The Conference strives to promote meaningful interaction between trainees and senior scientists from very diverse backgrounds to discuss current work, as well as stimulate new initiatives, and to foster collaborative interactions.